Strange shifting after Speedometer calibration

[Oysteinbno]

Hi.
I have a question to you all.
I have a 94 LT1 and a 4L60E transmission. The ECU is 16181333. I use the C.A.T.S software to program the ECU with PCM_EE definition file.
i've modified the 95 Corvette LT1 4L60E 1008.bin file by removing the VATS, and turned off some error messages in the ECM switch table.
When I do the Speedometer calibration, the transmission act strange. It slips in 3'rd gear and it also do strange kick downs.
Anyone knows why this happens ?

[lionelhutz]

Try it without letting the program change the transmission tables. Just calculate and put in the numbers for the speedometer scaling.

[Oysteinbno]

Hi again.
I Wich values should I use then:
"Speedometer Scalar", "Speedometer Scalar Fraction", "Speedometer Scalar Scantool" and "Time Between Pulses for Stop" ? Or should I skip the last one?

[lionelhutz]

When you use the calculator after you hit the calculate and apply buttons it pops up another window with a correction factor and says it will change a bunch of parameters. If you cancel that window then the transmission shifting stuff is not modified, just the speedometer calibration.

[Oysteinbno]

Now, I've tried to do this. But it still shifts strange from 3'rd to 4'th gear. When I cruse at around 35 MHP and just give a little throttle the transmission slips a lot ( in 4'th gear).I have to have over 50% throttle to make it shift downto 3'rd gear and then it works fine. Does this description make any sence?

:mad1:

[lionelhutz]

At this point you have to go in and modify the transmission settings yourself. You might have to increase the line pressure in the part of the curve where it's slipping and also modify the shift table and the kick-down table.

[steveo]

use a 94 automatic trans f-car bin. 94 and 95 transmission control are slightly different.

[lionelhutz]

I forgot about that but the 95 has the PWM TCC pressure solenoid that the 94 doesn't have. Best to start with a 94 bin to match the transmission. Still, that shouldn't affect the shifting.

[steveo]

yes, but this guy has yet to prove it's 'strange shifting' rather than 'improper lockup behavior that feels like weird shifting'. also haven't seen how that speedo calibration was done, post a screenshot of the speed calibration window in tunercat.

[lionelhutz]

I actually would expect it to throw a code for the TCC PWM solenoid and then not even attempt to lockup the converter. That's what my car did when I missed the PWM wire when making the swap harness.